The present invention relates to a control system for controlling a driving torque distribution between two drive wheels of a vehicle, and more specifically to a control system for controlling a clutch engagement force of a torque distributing clutch for varying a driving torque distribution between front and rear drive wheels of a four wheel driving vehicle or between left and right drive wheels.
A Japanese Utility Model Provisional Publication No. 63-22236(Application No. 61-115525) shows a conventional differential limiting clutch control system. This system increases a differential limiting force to prevent tack-in when a vehicle lateral acceleration is high and the vehicle is decelerated. However, this conventional system is arranged to increase the clutch engagement force in accordance with only the lateral acceleration. Therefore, when the clutch engagement force is increased so as to improve a high vehicle speed cornering stability, then the clutch engagement force becomes excessive and the vehicle becomes understeering in a low speed cornering operation. When, on the other hand, the clutch engagement force is held at a low level to improve a low speed steering response, then the high speed cornering stability becomes poor.